The reawakening of the sleeping X-ray pulsar XTE J1946+274
Abstract
We report on a series of outbursts of the high-mass X-ray binary XTE J1946+274 in 2010/2011 observed with INTEGRAL, RXTE, and Swift. We discuss possible mechanisms resulting in the extraordinary outburst behavior of this source. The X-ray spectra can be described by standard phenomenological models, enhanced by an absorption feature of unknown origin at about 10 keV and a narrow iron Kα fluorescence line at 6.4 keV, which are variable in flux and pulse phase. We find possible evidence for a cyclotron resonance scattering feature at about 25 keV at the 93% level. The presence of a strong cyclotron line at 35 keV seen in data from the source's 1998 outburst that was confirmed by a reanalysis of these data can be excluded. This result indicates that the cyclotron line feature in XTE J1946+274 is variable between individual outbursts.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2012
- DOI:
- 10.1051/0004-6361/201219580
- arXiv:
- arXiv:1209.1918
- Bibcode:
- 2012A&A...546A.125M
- Keywords:
-
- X-rays: binaries;
- accretion;
- accretion disks;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 9 pages, 8 figures, accepted for publication in A&